Ultrastructure of the esthesioneuroblastoma.

A tumor in the anatomic location and with the light microscopic appearance of an esthesioneuroblastoma was examined with the electron microscope. Secretory-type granules, cytoplasmic fibrils, and microtubules similar to those described in neuroblastomas were found in many of the tumor cells, which supports an origin from the sympathetic autonomic nervous system. Similar organelles were found in three other nasal tumors considered to be esthesioneuroblastomas, but their detail was obscured because they were examined after being initially processed in paraffin.